1. Field of the Invention
The invention pertains to chemicals for herbicidal use.
2. Description of the Prior Art
Although polyhalocarboxylic acids and the alkali metal, alkaline earth metal, primary, secondary and tertiary lower alkylamine and lower alkanolamine polyhalocarboxylate salts are used commercially for the control of undesirable grasses, their use in combination with a wild oat herbicide effective for the control of Avena fatua, Avena sterilis, or Avena ludoviciana is not suggested by the prior art. When acceptable known wild herbicides are used in combination with other herbicidal agents, problems are generally encountered. This is evidenced by the fact that the most widely accepted wild oat herbicides, 4-chloro-2-butynyl N-(3-chlorophenyl)carbamate (BARBAN) and the ethyl ester of N-benzoyl-N-(3,4-dichlorophenyl)alanine (SD-30053), are not effective in control of wild oats when used in combination with other herbicides. For example, J. D. Nalewaja, North Dakota State University, Fargo, N.D., reported in The Research Report of the North Central Weed Control Conference, 1971, pages 32-33, in a paper entitled "SD- 30053 Plus Broadleaf Herbicides," that at one pound per acre SD-30053 alone applied at the four-leaf stage of wild oats gave 70% control of wild oats. However, when applied in admixture at the same one pound per acre rate for SD-30053 plus 6 or 12 ounces per acre of 2,4-D, wild oat control dropped to 29% and 25%, respectively. Similarly, addition of 2 and 4 ounces per acre of DICAMBA to SD-30053 and 4 or 8 ounces per acre of BROMOXYNIL to SD-30053 reduced wild oat control to 29%, 24%, 53% and 53%, respectively. DICAMBA is 2-methoxy-3,6-dichlorobenzoic acid; BROMOXYNIL is 3,5-dibromo-4-hydroxybenzonitrile and 2,4-D is 2,4-dichlorophenoxyacetic acid.
It is, therefore, surprising to find that the combination of 1,2-dialkyl-3,5-diphenylpyrazolium compound with polyhalocarboxylic acids or the alkali metal, alkaline earth metal, lower alkylamine or lower alkanolamine salts of polyhalocarboxylates which are generally used for control of undesirable grasses is compatible and selective for wild oats to other undesirable grasses.